Induction-regulator.



C. B. MILLS.

INDUCTION REGULATOR.

APPLICATION FILED SEPT. 28. m2.

1,177,349. Patented Mar. 28,1916.

Illlllll llllll! INVENTQR ATTORNEY UNITED STATES PATENT OFFICE.

CHESTER B. MILLS, OF EAST MGKEESPORT, PENNSYLVANIA, ASSIGNOR TO WESTING-HOUSE ELECTRIC AND MANUFACTURING COMPANY, A. CORPORATION OF PENNSYL-VANIA.

INDUCTION-REGULATOR.

Specification of Letters Patent.

Patented Mar. 28, 1916.

Application filed September 28, 1912. Serial No. 722,971.

The object of my invention is to provide 1 means, for promptly adjustingthe movable part of a regulator of the class above indicated, withoutsubjecting the operating mechanism to excessive shocks or wear thatshall be dependent upon predetermined variations in an electric circuit,with which the regulator is associated.

A continuously operating electric motor has hitherto been employed foradjusting the movable member of an induction regu-' lator in the one orthe other direction, in response to variations on a regulated circuit,friction clutches and suitable gearing bein interposed between the motorshaft and the movable member ofthe regulator for establishing suitabledriving connections. An arrangement of this character has the advantageof producing relatively quick adjustments of the regulator and,-consequently, the regulating system in which it is embodied can be maderelatively sensitive. It has the disadvantage, however, of very uicklyaccelerating, in either the .one or t e other direction, a relativelylarge mass which not only necessitates the use of a relatively powerfulmotor but also large and strong clutches in order to avoid excessivewear. 3

According to' my present invention, I avoid the use of mechanicalclutches of any kind and, while I employ a continuously operating motor,it is so arranged as to easily effect the necessary adjustment of themovable member of the regulator without severe strains or shocks on anyof the parts of the mechanism. r

Figure 1 of the accompanying drawings is a plan view and Fig. 2 isapartially sectional elevation of the operating mechanism whichforms apart of my invention. Fig. 3 1s a d1agrannnat1c view of a regulat ngsystem arranged in accordance with my in-' vention and embodying theoperating mechanism of the other figures. I

Referring to Figs. 1 and 2 of the drawings, the operating mechanismcomprises a' continuously operating electric motor 1 and a pair ofdynamo-electric machines 2 and 3,

preferably of the induction type, having rotatable primary members 4 and5 and r0- tatable secondary members 6 and 7, respectively.

The secondary members 6 and 7 are preferably of the squirrel cage typeand are mounted on the same shaft 8 on opposite sides of a worm gear 9.One end of the motor shaft 10 is geared to the rotatable primary member5 of the dynamo-electric machine 3 by spur gears 11, 12 and 13, and theopposite end of the motor shaft is operatively connected to the primarymember 4 of the dynamo-electric machine 2 by spur gears 14 and 15.

The arrangement of parts is such that the motor is continuously drivingthe primary.

member 5 in one direction and the primary member 4 in the oppositedirection of rotation, the rotatable secondaries 6 and 7, which aresecured to the same; shaft,-being normally at rest except, when themovable member of the regulator is adjusted, as hereinafter pointed out.

The primary members 4 and 5 exert a torque upon thev secondary members 6and 7, respectively, only when current is supplied to the respectiveprimary windings 16 and 17, because, under these conditions only, arerotating magnetic fields produced which may influence the secondarymembers 6 and 7. herefore, whenthe primary windings of one of thedynamo-electric machines 2 or 3 are energized, a torque is exerted uponthe corresponding secondary member .6 or 7 which causes the lattertorotate at substantially the same speed as the rotating magnetic fieldproduced by the current flow through the corresponding primary winding,as hereinafter pointed out.

In order to make the. operations of the dynamo-electric machines 2 and 3perfectly clear, one of them will first be discussed.

Considering the machine 2, which is shown in Fig. 3 as a split-phasemachine of a well known type if primary member 4 is assumedto bestationary when electric energy is supplied to thesplit-phase winding16, a rotating magnetic field is produced which rotates relative to theprimary member at synchronous speed. This rotating field which resultsfrom the alternating currents flowing through the split-phase winding 16tends to cause the secondary member 6 to rotate at the same speedinasmuch as the actual difference in speed, or the slip, may beneglected in this discussion.

Ifthe primary member 4 be assumed to rotate at one-half synchronousspeed, in a direction opposite to the rotation of the rotating magneticfield produced by its windings, the actual speed of rotation of therotating magnetic field, relative to a stationary body, will besubstantially one-half synchronous speed. It is presumed that thewinding is so interconnected as to generate a rotating magnetic fieldwhich rotates in a direction opposite to that of the primary member 4.Consequently, under these conditions, the secondary member 6 tends torotate in a direction opposite to that of the primary member and atsubstantially the same speed as the primary member, inasmuch as the slipis assumed to be negligible.

If it isassumed that the primary member is rotated in the same directionas the r0- tating magnetic field which is produced by the winding 16 andat one-half synchronous speed, the rotating magnetic field Will then berotating relative to a stationary body at one and one-half timessynchronous speed and the secondary member 6 will tend to rotate in thesame direction as the primary member at a speed 50% above synchronousspeed or 100% above the speed of rotation of the primary member 4. Itis, therefore, possible, by driving the primary member 4 in the one Orthe other direction and suitably energizing its winding, to produce arotation of the secondary member 6 such as is desired for the adjustmentof the regulator.

.By driving the primary members 2 and 3 in opposite directions atsubstantially onehalf synchronous speed and opposite to the rotatingmagnetic fields produced by their respective windings16 and 17, whenenergized, the shaft 8 and the secondary members 6 and 7, which aresecured thereto, will be operated in either the one or the otherdirection at substantially one-half synchonous sp ed, according as thewinding 16 or the win ing 17 is energized.

Referring to Fig. 3 of the drawings, the system here shown comprises theoperating mechanism of Figs. 1 and 2 (which bears the same referencecharacters in all of the 'figures) a regulator 18, having a stationarycoil 29 of the primary relay switch 22. The

coil 29, when thus energized above normal, actuates a lever 30 inopposition to a spring 31, and throws a movable contact member 32 intoengagement with a stationary contact member 33. A circuit is thencompleted from a conductor 34 of an alternating current auxiliary sourceof energy, through a resistor 35, the contact members 32 and 33, aconductor 36, magnet coil 37 of the secondary relay 23, and a conductor38 to the opposite conductor 39 of the auxiliary source. I

When the secondary relay switch coil37 is energized, a movable contactmember 40 is moved into engagement with a stationary contact member 41and another circuit is completed from the conductor 34, through aconductor 42, the contact members 40 and 41, a conductor 43, a limitswitch 44, a conductor 45, a brush 46, a collector ring 47 of thedynamo-electric machine 3, primary windings 48 of the same machine, acollector ring 49, a brush 50 and a conductor 51 to the conductor 39.The primary member of the machine, when thus energized, exerts a torqueupon the secondary member 7 and causes it to rotate at a predeterminedspeed in the desired direction. NVhen the windings 48 are energized, aprompt rotative adjustment of the shaft 8 and the movable member of theregulator is effected. The acceleration of the shaft 8 and theadjustment of the regulator are, however, ef-

' fected without subjecting either the driving or the driven parts tosevere strains or shocks.

The arrangement of parts is such that the movable member 20 of theregulator 18 is so adjusted, when the primary windings 48 are energized,as to decrease the voltage of the distributing circuit 24 25 As long asthe potential of the distributing circuit is substantially constant at apredetermined value, the coil 29 of the primary relay switch 22 will beso energized as to balance the spring 31 and hold the movable contactmember 32 between and out of engagement with the stationary contactmembers 33 and 33.

If thevoltage of the distributing circuit falls slightly below theaforesaid predetermined value, the spring 31 will overcome the action ofthe magnet 29 and will move the contact member 32 into engagement withthe stationary contact member 33. Under these conditions, a circuit iscompleted from the conductor 34, through the resistor 35, the

I switch is energized, the contact member 40 is moved into engagementwith astationary contact member 54, completing a circuit from theconductor 42, through the contact members 40 and 54, a conductor 55, alimit switch 56, a conductor 57 a brush 58 and a collector ring 59 ofthe dynamo-electric machine 2, primary windings 60 of the same machine,a collector ring 61, a brush 62 and the conductor 51 to the conductor39. It is, therefore, evident that the primary windings 48 and 60 of thedynamo-electric machines 3 and 2 are respectively energized according ascoil 37 and 53 of the secondary relay switch 23 is energized. Thesecondary relay switch coils are energized in accordance with theposition of the primary relay switch 22 and are, consequently,indirectly responsive to fluctuations above and below a predeterminedvalue in the voltage of the distributing circuit 24 and 25.

y tion between the movablemember 20 of the regulator and the shaft 8,the movable member is adjusted through a relatively small angle byseveral rotations of the shaft.

The limitswitches 44 and 56 are'provided for the purpose of preventingover-running of the movable member of the regulator in either directionand, inasmuch as they form no part of my present invention, any suitableswitch structure may be employed. As illustrated in Fig. 1 of thedrawings, the limit switches each comprise an arm or contact finger 63which is pivotally supported and is provided with a latch 64 to hold theswitch closed and is adapted to be tripped by an arm 65 that is carriedby a gear segment 66 which meshes with the worm gear 9, and is siciredto the upper end of the regulator s a t.

If the voltage of the distributing circuit either increases or decreasesto such an extent that the regulator is unable to correct it, theregulator will be adjusted in such direction as to effect the propercorrection until one of the limit switches is tripped, the arrangementof parts being such that the circuit, through which the active primarywinding is energized, is then interrupted and the regulator permitted tocome to'rest. The regulator, however, is still operative, since theother limit switch is closed, and may be adjusted in the reversedirection as soon as the voltage of the distributing circuit isrestoredto normal and fluctuates in the opposite direction;

The operating mechanism of my invenreason of the worm and wheelconnecmary members,

tion is adapted for various uses, although it is particularly applicableto automatic regulators of the induction type.

While I have shown the dynamo-electric machines 2 and 3 as split-phasemachines which are supplied with single phase alternating current fromthe supply mains 34- 39, it will be understood that the machines 2 and 3may be replaced by other types of dynamo-electric machines which arewell known in. the art and which produce rotating magnetic fields toinfluence the secondary members 6 and 7, as hereinbefore mentioned. Forthe purposes of my invention, dynamo-electric machines supplied withpolyphase alternating currents may be substituted for the machines 2 and3 inasmuch as the action of the former, in producing rotating magneticfields which, in turn, effect propulsion of the secondary members 6 and7 is an equivalent, within the confines of my invention, of thatproduced by the dynamoelectric machines 2 and 3.

I desire that variations which do not depart from the spirit of myinvention shall be included within its scope.

I claim as my invention:

1. The combination with a driven member, and a pair of dynamoelectricmachines having one pair of rotatable members 0-peratively connected tothe driven member and a second pair of rotatable members, the members ofat least one of said pairs being provided with windings which may beselectively energized with alternating currents vwhen energized withalternating currents,

of means for rotating the primary members of the two dynamo-electricmachines and means for automatically selectively energizing the.windings of said primary members.

3. The combination with a regulating element, apair of dynamo-electricmachines having secondary members operatively connected to theregulating element, rotatable primary members and windings thereforwhich generate rotating magnetic fields when energized'with alternatingcurrents, of means for rotating the primary members of the twodynamo-electric machines in opposite directions, and automatic means forselectively energizing the windings of the priwhereby the regulatingelement is adjusted in the one or the other direction.

4. The combination with a regulating element, a pair of dynamo-electricmachines having rotatable secondary members operatively connected to theregulating element, rotatable primary members and windings thereforwhich generate rotating magnetic fields when energized withalternatingcur-v rents, of a continuously operating electric motor for driving theprimary members in opposite directions, and automatic means forselectively energizing the primary windings of the two dynamo-electricmachines to generate rotating magnetic fields which will influence theone or the other of the secondary members as to selectively adjust theregulating element in the one or the other direction. I

5. In a regulating system, the combination with a regulated element, aregulator having a movable member, a pair of dynamo-electric machineshaving secondary members operatively connected to the movable member ofthe regulator, rotatable primary members and windings therefor whichgenerate rotating magnetic fields when energized with alternatingcurrents, of means for continuously operating the primary members inopposite directions, and means responsive to variations in the regulatedelementfor selectively energizing the primary windings of saiddynamo-electric machines.

6. In a system of regulation, the combination with a distributingcircuit, an electric regulator associated therewith and having a movablemember, a pair of dynamoelectric machines, and secondary membersoperatively connected to said member,.rotatable primary members andwindings therefor which generate rotating magnetic fields when energizedwith alternating currents, and an electric motor for continuously operating the primary members in opposite directions, of a primary relaythat is de- (a pendent upon electrical fluctuations in the distributingcircuit for automatically and selectively energizingthe one or the otherof the primary windings.

7. In a regulating system, the combination with an alternating currentdistributing circuit, a transformer regulator associated therewith andhaving a movable member, a pair of dynamo-electric machinesvof thesplit-phase type having rotatable secondary members provided withsquirrel cage windings and operatively connected to the movable memberof the regulator, rotatable primary members having windings normallydeenergized, said windings generating rotating magnetic fields whenenergized with alternating currents, an alternating current motor-forcontinuouslv operating the primary members in opposite directions, and

means dependent upon fluctuations in voltage in the distributing circuitabove and be low a predetermined value for automatically and selectivelyenergizing the primary windings of the dynamo-electric machines.

8. The combination with a drivenmember, a pair of dynamo-electricmachines, each having a rotatable primary and a rotatable secondarymember, one at least of which is provided with a winding to generate arotating magnetic field when energized with alternating current, onemember of each machine being continuously operated and the other memberof each being operatively connected to the driven member, of automaticmeans for selectively energizing the two dynamo-electric machines toproduce opposite rotative adjustments of the driven memben.

In testimony whereof, I have hereunto subscribed myname this 21st day ofSept.,

' CHESTER B. MILLS. Witnesses:

' THos. I FISHER,

B. B. I-Imns.

